Intelligent environmental sensor for irrigation systems

ABSTRACT

The invention provides a regulator system for regulating the operation of an irrigation system which is responsive to user programmed information. It has a control element for issuing watering control signals to an irrigation system, having at least one of (i) a duration programming device for programming a minimum amount of time and a maximum amount of time for the suspension of watering by the irrigation system, and (ii) a user adjustable temperature programming device for programming a minimum allowed temperature for initiating a watering period by the irrigation system. It further has an irrigation system interface for connecting said control element with the irrigation system. It also has a switch for conveying the control signals from the control element to the irrigation system via the irrigation system interface, for either permitting or prohibiting watering by the irrigation system, responsive to the control signals generated by and received from the control element.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/157,253 filed Jun. 9, 2011 entitled IntelligentEnvironmental Sensor For Irrigation Systems, which is a continuation ofU.S. patent application Ser. No. 12/855,615 filed Aug. 12, 2010 entitledIntelligent Environmental Sensor For Irrigation Systems (now U.S. Pat.No. 7,962,245 issued Jun. 14, 2011), which is a continuation of U.S.patent application Ser. No. 12/104,937 filed Apr. 17, 2008 entitledIntelligent Environmental Sensor For Irrigation Systems (now U.S. Pat.No. 7,912,588 issued Mar. 22, 2011), which is a continuation of U.S.patent application Ser. No. 11/314,451 filed Dec. 20, 2005 entitledIntelligent Environmental Sensor For Irrigation Systems (now U.S. Pat.No. 7,363,113 issued Apr. 22, 2008), which is a continuation of U.S.patent application Ser. No. 10/690,694 filed Oct. 22, 2003 entitledIntelligent Environmental Sensor For Irrigation Systems (now U.S. Pat.No. 7,010,394 issued Mar. 7, 2006), which claims benefit of U.S.Provisional Patent Application Ser. No. 60/421,613, filed Oct. 24, 2002entitled Intelligent Environmental Sensor For Irrigation Systems; all ofwhich are incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a system for regulating the operationof an irrigation system. More particularly, the invention pertains to aregulator system for regulating the operation of an irrigation systemwhich is responsive to user programmed information.

Description of the Related Art

Automatic irrigation systems such as those employed for landscape andagricultural watering are well known in the art. Typical irrigationsystems use a means of controlling the watering cycles via an automaticcontroller. The need to control watering cycles due to environmentalconditions is important for saving costs and preventing unsafeconditions. Watering cycle controls must be responsive to precipitation,high wind and freezing temperature situations. The usual means ofsuspending an automatic watering cycle in an irrigation system is by anoperator manually canceling a cycle at an irrigation controller. At mosttimes this proves to be unreliable and inconvenient due toinconsistencies by the operator. Often an operator ignores the need tosuspend the watering cycle, and/or neglects to resume the watering cyclewhen required. This leads to over-watering and under-watering of thelandscaping.

Rain sensors for irrigation systems are an effective and economicalmethod of conserving water, energy, and costs. One such rain sensor foran irrigation system is described in U.S. Pat. No. 6,452,499, which isincorporated herein by reference. This patent shows an easy to installrain sensor which wirelessly transmits rain sensor data to an irrigationsystem. The data is wirelessly received at a control mechanism andaffects the operation of the irrigation controller as desired.

One drawback of currently available rain sensors is the inability toeffectively change the control parameters for choosing the environmentalconditions for allowing or suspending watering by the irrigation system.Existing systems have some major disadvantages in that typical rainsensors are factory pre-set for the environmental conditions forallowing or suspending watering by the irrigation system or are onlyadjustable at the remote sensing location. Known weather sensorsinterface with an irrigation controller to prevent or resume wateringdependent upon local weather conditions such as rain, temperature, andwind conditions. For example, a rain and freeze sensor would communicateto the irrigation controller and prevent watering of lawns and landscapewhen it is raining, has rained recently or the temperature is too low.

However, once installed and adjusted, rain sensors do not allow forparameter adjustments to be made by an individual at the irrigationcontroller. Also, existing systems are not able to interpret the inputreceived from the sensor. Typically the sensor either makes or breaks anelectrical circuit and thereby prevents the irrigation controller fromwatering by either breaking a connection to a common solenoid, valve orwire or by connecting to special sensor inputs on the controller. Theextent by which existing systems can be controlled is limited tosensitivity adjustments of the sensor unit such as for the amount ofaccumulated rainfall required to trip the sensor. Also, typically,weather sensors are mounted where they are exposed to the elements andonce mounted are not easily adjusted or manipulated. Hence there is aneed for the ability to control a weather sensor from an interface ofthese sensors or sensor systems with the irrigation controllers to whichthey are connected.

It would be advantageous for the operator to be able to program varyingenvironmental conditions for changes to meet seasonal or geographicrequirements. The present invention provides a device, method, andsystem for controlling a weather sensor for irrigation systems wherebythe input obtained from the weather sensor is intelligently interpretedin order to provide increased functionality and redundancy in a givenweather sensor installation. The invention employs a design and methodallowing for the user or irrigation system installer to quickly andeasily adjust control values or limits for the weather sensor such asthe minimum and maximum amount of time the sensor is permitted to leavethe irrigation system in the inactive state thus allowing for dynamic,user settable environmental control parameters. Maximum time settingsalso have the added advantage of being a system failsafe which canprevent landscape loss due to lack of water should there be a sensorfailure. Through the use of a microprocessor or other form of controlcircuitry, weather sensors for irrigation systems, whether wired orwireless, can be programmed to behave in a certain fashion based oninputs received from the sensors themselves. The invention utilizescontrol circuitry to enable intelligent decisions to be made at, near,or within the irrigation controller and also at the sensors themselves.The invention also include user settable temperature limits that allowthe user to actively set the temperature below which the sprinklersystem will remain off due to the risk of frozen vegetation or the icingof walkways should the system activate when the ambient temperature istoo low. Another feature of the invention utilizes separate rain sensorfunctions such that one switch activates rapidly due to rain, whileanother activates after a certain amount of rain falls and accumulates.This feature has the benefit of allowing decisions to be made either atthe sensor itself or at the receiver or irrigation controller. It allowsfor a sensor switch to be eventually ignored should it not be followedby the other switch activating indicating sufficient rainfall andtherefore not requiring sprinkler deactivation. In this instance, thesprinkler system would be deactivated upon the sensor elementtriggering, however the system is programmed to resume in its activestate should the second, accumulation type sensor not trigger within acertain amount of time. Another feature of the invention allows for thecontrol of an irrigation system by more than one sensor type, such as arain sensor and a temperature sensor—while utilizing either a wiredfeedback system or a wireless system. Both wired and wireless systemsallow the system to interpret whether a rain signal or a temperaturesignal is being applied by using a varied data signal, or variedelectrical resistance. This feature has the advantage of allowing thesensor data to be received and interpreted based on the certaincondition being sensed as opposed to sending a simple on/off type datasignal. This allows for combination of weather conditions to beintelligently interpreted and to provide for better control of theirrigation system.

SUMMARY OF THE INVENTION

The invention provides a regulator system for regulating the operationof an irrigation system, responsive to user programmed information,comprising

a) a control element for issuing watering control signals to anirrigation system, comprising at least one of (i) a duration programmingdevice for programming a minimum amount of time and a maximum amount oftime for the suspension of watering by the irrigation system, and (ii) auser adjustable temperature programming device for programming a minimumallowed temperature for initiating a watering period by the irrigationsystem;

b) an irrigation system interface for connecting said control elementwith the irrigation system;

c) a switch for conveying the control signals from the control elementto the irrigation system via the irrigation system interface, for eitherpermitting or prohibiting watering by the irrigation system, responsiveto the control signals generated by and received from the controlelement.

The invention also provides a regulator system for regulating theoperation of an irrigation system, responsive to user programmedinformation, comprising

a) a control element for issuing watering control signals to anirrigation system, comprising both (i) a rainfall detection sensor whichis capable of sensing whether rain is currently falling or a rate ofrainfall, and which wirelessly transmits control signals to theirrigation system responsive to a rain currently falling condition, and

(ii) a rainfall accumulation sensor which is capable of sensing aquantity of accumulated rainfall, and which wirelessly transmits awatering signal or a watering suspension signal to the irrigationsystem; wherein each of the signals from the rainfall detection sensorand the rainfall accumulation sensor are independently recognized by theirrigation system and independently cause a response by the irrigationsystem;

b) an irrigation system interface for connecting said control elementwith the irrigation system;

c) a switch for conveying the control signals from the control elementto the irrigation system via the irrigation system interface, for eitherpermitting or prohibiting watering by the irrigation system, responsiveto the control signals generated by and received from the controlelement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show one installation layout of irrigation regulatorsystem according to the invention.

FIGS. 2A, B, C, and D show various configurations of irrigationregulator systems.

FIGS. 3A and 3B show two embodiments of a receiver portion of theirrigation regulator system.

FIG. 3C shows a hard-wired embodiment of the receiver portion of theirrigation regulator system.

FIGS. 4A and 4B show two embodiments of a wireless receiver portion ofthe irrigation regulator system.

FIGS. 5A and 5B show an interface between the irrigation controller andthe irrigation regulator system's hard-wired receiver control circuitry.

FIG. 6 shows a schematic representation of an irrigation regulatorsystem according to the invention and its positioning with respect to anirrigation system and an optional irrigation system controller.

FIG. 7. shows a flowchart for setting the microprocessor for the minimumand maximum number of days between waterings.

FIG. 8. shows a flowchart for setting the microprocessor for the minimumtemperature for watering.

FIG. 9. shows a flowchart for setting the microprocessor for monitoringa rainfall detection sensor and a rainfall accumulation sensor.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 6 shows a schematic representation of an irrigation regulatorsystem according to the invention and its positioning with respect to anirrigation system and an optional irrigation system controller. Theregulator system is shown to have a control element, a switch and aninterface. The regulator system is either directly connected to theirrigation system or indirectly connected to the irrigation systemthrough an intermediate irrigation system controller. Irrigation systemcontrollers are well known in the art and serve to control water flowthrough the irrigation system tubing, valves and spray heads, usually ona timed, pre-programmed basis. The regulator system of this inventioncan either by-pass the controller and regulate the irrigation systemdirectly, or in the preferred embodiment, the regulator operates toregulate the controller, and hence regulate the irrigation systemindirectly through the controller.

The control element issues watering control signals to the irrigationsystem. In one embodiment, the control element has either or both of (i)a duration programming device for programming a minimum amount of timeand a maximum amount of time for the suspension of watering by theirrigation system, and (ii) a user adjustable temperature programmingdevice for programming a minimum allowed temperature for initiating awatering period by the irrigation system.

In the usual case, the duration programming device programs a minimumnumber of days and a maximum number of days for the suspension ofwatering by the irrigation system. In the preferred embodiment, theduration programming device, which may be digital or analog, comprises amicroprocessor or programmable logic controller (PLC), and a clock whichare mounted in a housing. The microprocessor or PLC is programmed forirrigation time and duration changeability by an operator throughappropriate controls such as buttons or knobs on the housing. Thecontrol element also has a temperature programming device. In the usualcase, the user adjustable temperature programming device programs aminimum allowed temperature for initiating a watering period by theirrigation system. In the preferred embodiment, the temperatureprogramming device, which may be digital or analog, comprises amicroprocessor or PLC which is mounted in the housing with a remotelylocated thermometer relaying temperature data to the regulator systemreceiver. The microprocessor or PLC is programmed for temperaturechangeability by an operator through appropriate controls such asbuttons or knobs on the housing. The duration programming device and thetemperature programming device may share the same microprocessor or PLC.Usually the control element has both a duration programming device and atemperature programming device.

The control element controls a switch, as shown in FIG. 6, which sendsthe appropriate control signal to the irrigation system through anirrigation system interface. The switch conveys control signals from thecontrol element to the irrigation system via the irrigation systeminterface, for either permitting or prohibiting watering by theirrigation system, responsive to the control signals generated by andreceived from the control element. The switch may be a toggle switch, arelay, an EPROM or other programmable switch, or other data controlmechanism. The switch may also be a part of the above mentionedmicroprocessor or PLC. The interface may be a wired or a wirelessconnection between the control element and the irrigation system orirrigation system controller. Wireless connections include a radiofrequency, infrared, or ultrasonic transmitter for wirelesslytransmitting control signals to the irrigation system. The transmittermay be operated by an energy source such as an electric power line, abattery, solar energy, light energy, hygroscopic expansion energy, windenergy, temperature dependent expansion energy, and combinationsthereof. The invention also allows for wireless transmission to occur atnon-predetermined intervals. Rather than sending transmissions based onregular time intervals, the invention allows for transmissions to besent based on a sensed change of an environmental condition. Forinstance, a transmission can occur every time rainfall is sensed,additionally transmissions can be made due to temperature changes toallow for system redundancy wherein multiple transmissions can be sentto validate sensor status. This feature has the additional advantage offalling under Part 15 of the FCC rules for unlicensed wirelesstransmitters whereby a higher output power is allowed sincepre-determined intervals for transmissions are not used. The regulatorsystem may further have a bypass switch which allows the current stateof the control element to be ignored. The bypass switch may beautomatically resetting based on a change in state of the controlelement.

In another embodiment of the invention, the control element may furthercomprise a rainfall detection sensor which is capable of sensing whetherrain is currently falling or a rate of rainfall, and which transmitscontrol signals to the irrigation system responsive to a rain currentlyfalling condition or a rate of rainfall. Preferably such a rainfalldetection sensor alternatively wirelessly transmits a watering signal ora watering suspension signal to the irrigation system. Rainfalldetection sensors are known in the art.

In another embodiment of the invention, the control element may furthercomprise a rainfall accumulation sensor which is capable of measuring aquantity of accumulated rainfall; and which alternatively transmits awatering signal or a watering suspension signal to the irrigation systemresponsive to a quantity of accumulated rainfall condition. Preferablysuch a rainfall accumulation sensor alternatively wirelessly transmits awatering signal or a watering suspension signal to the irrigation systemresponsive to a quantity of accumulated rainfall condition. Rainfallaccumulation sensors are known in the art and may comprise a hygroscopicmaterial that expands upon contact with moisture from water vapor, rain,snow, or ice. The rainfall accumulation sensor may be attached to arainfall accumulation sensor switch which is connected mechanically tothe hygroscopic material and electrically to a transmitter. Atransmitter is preferably wirelessly connected to the irrigation system.The rainfall accumulation sensor switch is responsive to the hygroscopicmaterial expanding a given amount indicative of a predetermined level ofatmospheric precipitation. The rainfall accumulation sensor switchenables the transmitter to transmit signals to the irrigation systemindicative of an atmospheric precipitation condition and hence allowingwatering or causing watering suspension.

In another alternative, the regulator system may further have a remotelylocated receiver receptive of wireless signals from a transmitter, forconverting the wireless signals into electrical control information, forapplication to the control element for affecting timed preprogrammedoperation of the irrigation system. In this case, the control element isresponsive to the presence of electrical control information forterminating any present or programmed future operation of the irrigationsystem, and further responsive to the termination of electrical controlinformation for resuming timed preprogrammed operation of the irrigationsystem. The receiver may have a signal strength indicator which servesas an installation aid so that the installer can manipulate both areceiver and transmitter in order to obtain the strongest signal for anygiven installation. When working with wireless devices, this type ofinformation saves installer time, and provides an ongoing indicator forthe property owner of the device because the signal strength can bemonitored over time to assure proper functioning of the installed unit.

In an alternate embodiment of the invention the control elementcomprises both (i) a rainfall detection sensor which is capable ofsensing whether rain is currently falling or a rate of rainfall, andwhich wirelessly transmits control signals to the irrigation systemresponsive to a rain currently falling condition, and (ii) a rainfallaccumulation sensor which is capable of sensing a quantity ofaccumulated rainfall, and which wirelessly transmits a watering signalor a watering suspension signal to the irrigation system. Each of thesignals from the rainfall detection sensor and the rainfall accumulationsensor are independently recognized by the irrigation system andindependently cause a response by the irrigation system. In one case thesignal from the rainfall detection sensor is ignored by the irrigationsystem after a predetermined period of time if a signal from therainfall accumulation sensor is not received by the irrigation systemwithin the predetermined period of time. In another case thepredetermined period of time, the amount of rainfall detected by therainfall detection sensor for transmitting a control signal, and theamount of rainfall accumulated by the rainfall accumulation sensor fortransmitting a control signal are programmable for variability. In thesealternate embodiments, the control element comprises an adjustablerainfall detection sensor, and an adjustable rainfall accumulationsensor together with the appropriate microprocessor or PLC for the wiredor wireless transmission of a watering signal or a watering suspensionsignal to the irrigation system.

The herein described regulator system may further include additionalsensors such as a light sensor, a pressure sensor, a wind sensor, andcombinations thereof, connected to the irrigation system and whicheither permit or prohibit watering by the irrigation system, responsiveto a signal generated by a sensed condition.

FIGS. 1A and 1B show installation layouts and placements of the typicalirrigation regulator system according to the invention. The irrigationregulator system includes an environmental 2 mounted on a structure 16which communicates with a remotely located irrigation controller 18.FIG. 1A shows a hard-wired installation where environmental sensor 2 andits control circuitry 4 are wired via sensor data/communication wiring20, to a receiver 10 and its control circuitry 12. The receiver in turnis interfaced with irrigation controller 18, which communicates with therest of the irrigation system 14, via irrigation controller communicator22. The same features apply for FIG. 1B except that the information istransmitted via a wireless communication signal 8.

FIGS. 2A, 2B, 2C, and 2D show various configurations of an irrigationregulator system sensor according to the invention. FIG. 2A shows ahard-wired irrigation regulator system sensor with control circuitry 4,that communicates via data/communication wiring 20. FIG. 2B shows awireless irrigation regulator system sensor using a wireless transmitter6 to communicate data to the irrigation controller. FIG. 2C shows theuse of two different types of precipitation sensors that are bothinterfaced with the control circuitry 4 in order to allow the sensorcontrol circuitry or the receiver control circuitry to determine how tocontrol the irrigation system based on inputs received from one or bothof the sensors. This allows the irrigation regulator system to actrapidly to turn off irrigation should the rainfall detection sensor 27,become activated. It would then only keep the irrigation system off ifthe rainfall detection sensor activation was followed by the rainfallaccumulation sensor 23, activating within a predetermined amount oftime. FIG. 2D shows a wireless irrigation regulator systemtransmitter/sensor that employs both a rain sensor mechanism and alsoincorporates a temperature sensor 28, that both interface into controlcircuitry 4. FIG. 2D also shows how two different types of sensors canbe fed into the same control circuitry, whether at the sensor itself orat the receiver connected via communication wiring 20, as shown in FIG.2A. In this particular embodiment, a rainfall accumulation sensor 23,and a temperature sensor 28, are shown.

FIGS. 3A and 3B show two embodiments of a receiver portion of theirrigation regulator system. FIG. 3A shows an embodiment having rainsensor controls in a housing 11. Set and mode buttons 35, 36 provide foruser input and increased functionality at the receiver and via theindicator lights, namely, a minimum days indicator light 30, a maximumdays indicator light 31, a rain delay indicator light 32, a signalstrength/number indicator light 33, and a low battery indicator light34, which provide the ability to manipulate how data is interpreted andhow the irrigation system is controlled. Bypass button 37 shows howactivation of a system by-pass is enabled, and light 38 is a system offor rain indicator. FIG. 3B shows an embodiment where a rain and freezesensor data apply to a receiver with freeze indicator 40 and a useradjustable temperature indicator 41. A digital LCD or LED 39 may also beused. FIG. 3C shows a hard-wired receiver interface with sensor datawiring 20 and receiver controller interface wiring 50 Also to be notedon FIG. 3C is the series of indicator lights 33, that act as numericalindicators for adjusting minimum days, maximum days, and rain delay,since signal strength does not apply to a hard-wired type unit.

FIGS. 4A and 4B show how wireless receiver 10 and receiver controlcircuitry 12 interface with an irrigation controller 18. FIG. 4B showshow the receiver 10 and receiver control circuitry 12 can be integrallyhoused within the irrigation controller 18. In both these embodiments,the control circuitry 12, interfaces with the controller 18, viareceiver/controller interface wiring 50. FIGS. 3A and 3B show thewireless receiver interface. These receiver interfaces, apply to bothhard-wired and wireless systems, with the only exceptions being thatthere is no application for signal strength or a battery low indicatorwith a hard-wired receiver. FIG. 3C shows more specifically thehard-wired receiver interface. The user or installer, through the use ofthe mode and set buttons, can change system control parameters at thereceiver without having to adjust the sensor at all. The user has theability to set the minimum number of days that an irrigation system isto remain off after a rain or freeze activation by applying a set pointin the minimum days data register. Likewise the user can set theabsolute maximum number of days the irrigation system will remain offdue to a rain or freeze activation. A rain delay feature is alsoincorporated whereby the user can set the number of days the irrigationsystem will remain off regardless of whether or not any of the sensorsbecome active—this feature also has the added benefit of being able tobe automatically turned off should any of the sensors become activeduring the set period of the rain delay. As shown in FIG. 3B, when atemperature sensor is employed and provides the ability to apply a settemperature at which point, and temperatures below, the irrigationsystem will be turned off due to freezing/icing hazards. The userinterface is simple in that by pressing the mode button, differentindicator lights will illuminate, then by pressing the set button, thevalue for the illuminated mode can be changed. For example, by pressingthe mode button 36 until the Max Days light 31 illuminates, the user canthen press the set button 35 to increment the signal/numerical lights33, to set the number or days into the data register.

FIGS. 5A and 5B show the interface between the irrigation controller 18and the hard-wired receiver control circuitry 12.

FIG. 7 shows a flowchart for the minimum and maximum days betweenwatering cycles. The user inputs sets of variables via a receiverinterface, for example the minimum number of days MINDAYS (1, 2, 3, 4,or 5) and the maximum number of days MAXDAYS (6, 7, 8, 9 or 10). TheMINDAYS and MAXDAYS variables are then written to the microprocessormemory. If a sensor wet or sensor cold signal has been received, thereceiver is set into rain or freeze mode and all watering is nowsuspended. The variable ACTIVETIME is set=0 and a timer is started whichincrements ACTIVETIME with time elapsed. If the ACTIVETIME is greaterthan MINDAYS, and a sensor dry or sensor warm signal has been receivedand ACTIVETIME is not greater than MAXDAYS, then the receiver is setinto normal mode and watering is allowed.

FIG. 8 shows a flowchart of user settable temperature. The user inputs avariable via receiver interface, which includes a liquid crystal displayfor the minimum temperature MINTEMP, for example, 36° F. to 50° F. TheMINTEMP variable is then written to microprocessor memory. Sensortemperature data TEMP is transmitted periodically to the receiver. Ifthe TEMP is not greater than MINTEMP the receiver is set into freezemode, and all watering is suspended.

FIG. 9 shows a flowchart where two rain sensors, namely a quick reactingrainfall detector and a rainfall accumulation detector. The two separaterain sensors are connected to the transmitter microprocessor. Eachsensor can be identified separately by the microprocessor such as byusing separate microprocessor inputs. One sensor is a quick reactingrainfall detector using a sensing method such as rain dropletconductance or a small hygroscopic element connected to a switch. Theother sensor is an accumulation type rainfall detector using a standardhygroscopic disk stack element connected to a switch. The variable QRAINis written to the transmitter unit microprocessor memory when the quickreacting rainfall detector is active. The variable RAIN is written tothe transmitter microprocessor memory when the rainfall accumulationdetector is active. Sensor data (QRAIN and RAIN) are transmittedperiodically to receiver and also any time there is a change in eitheror both of these sensors, and hence variables. If the variables RAIN andQRAIN are active, the receiver is set into rain mode and all watering issuspended. If only the variable QRAIN is active, the variable QRAINTIMEis set=0 and a timer starts that increments QRAINTIME with time elapsed.If QRAINTIME is not greater than 30 minutes, the receiver is set intorain mode and watering is suspended. If QRAINTIME is greater than 30minutes and the variable RAIN is not active, the receiver is set intodry mode and watering is allowed and the QRAIN value is ignored until itchanges value again.

While the present invention has been particularly shown and describedwith reference to preferred embodiments, it will be readily appreciatedby those of ordinary skill in the art that various changes andmodifications may be made without departing from the spirit and scope ofthe invention. It is intended that the claims be interpreted to coverthe disclosed embodiment, those alternatives which have been discussedabove and all equivalents thereto.

What is claimed is:
 1. A system for regulating an irrigation systemcomprising: a sensor unit configured for operation at a remote locationcomprising: a wireless transmitter that wirelessly transmits data; and,a sensor assembly that is responsive to contact with rain, said sensorassembly including a hygroscopic sensor; and; a control moduleconfigured for operation local to an irrigation controller, comprising:a wireless communication unit that wirelessly receives said datawirelessly transmitted by said sensor unit; a module control circuit incommunication with said wireless communication unit and beingconnectable to said irrigation controller to interrupt an irrigationschedule; a user interface in communication with said module controlcircuitry and having a bypass switch that bypasses interruption of saidirrigation schedule by said module control circuit; wherein said sensorunit generates a quick reacting rainfall signal and an accumulationrainfall signal, and wherein said sensor unit and said control moduleare operable to rapidly interrupt said irrigation schedule uponinitiation of rain based on said quick reacting rainfall signal andmaintain interruption of said irrigation schedule based on saidaccumulation rainfall signal when said hygroscopic sensor exceeds auser-determined threshold of rain absorbed by said hygroscopic sensor.2. The system of claim 1, wherein said user interface further comprisesa signal strength indicator having a plurality of indication elementsarranged in a horizontal pattern for indicating a strength of a wirelesssignal transmitted from said wireless transmitter of said sensor unit.3. The system of claim 1, wherein said user interface further comprisesa battery indicator that indicates when a battery of said sensor unitreaches a predetermined level.
 4. The system of claim 1, wherein saidsensor unit further comprises a temperature sensor and wherein said userinterface displays a user-adjustable, temperature threshold forinterrupting said irrigation schedule of said irrigation controller. 5.The system of claim 1, wherein said sensor assembly comprises aplurality of vertically stacked, hygroscopic discs.
 6. The system ofclaim 1, wherein said sensor assembly comprises a first hygroscopicsensor and a second hygroscopic sensor.
 7. The system of claim 1,wherein said sensor assembly comprises a quick reacting rainfalldetector and an accumulation type rainfall detector.
 8. A system forregulating an irrigation system comprising: a wireless control elementconfigured for operation at a remote location comprising: a wirelesstransmitter that wirelessly transmits data; and, a sensor assembly thatis configured to measure multiple, different amounts of rain withoutuser adjustment, and including a hygroscopic sensor; a control moduleconfigured for operation local to an irrigation controller and beingdirectly connected to said irrigation controller, comprising: a wirelesscommunication unit that wirelessly receives said data wirelesslytransmitted by said wireless control element; a module control circuitin communication with said wireless communication unit; a user interfacein communication with said module control circuitry; wherein said sensorunit and said control module are connectable to said irrigationcontroller and rapidly interrupt an irrigation schedule executed by saidirrigation controller upon initiation of rain based on a quick reactingrainfall signal generated by said sensor unit, and wherein said sensorunit and said control module maintain interruption of said irrigationschedule until said sensor unit stops generating an accumulationrainfall signal communicating that a current measurement of saidhygroscopic sensor is less than a predetermined interruption thresholdof said hygroscopic sensor.
 9. The system of claim 8, wherein saidhygroscopic sensor assembly comprises a plurality of vertically stacked,hygroscopic discs.
 10. The system of claim 9, wherein said userinterface further comprises a signal strength indicator having aplurality of indication elements arranged in a horizontal pattern forindicating a strength of a wireless signal transmitted from saidwireless transmitter of said wireless control element.
 11. The system ofclaim 10, wherein said user interface further comprises a batteryindicator that indicates when a battery of said wireless control elementreaches a predetermined level.
 12. The system of claim 11, wherein saidwireless control element further comprises a temperature sensor andwherein said user interface displays a user-adjustable, temperaturethreshold for interrupting said irrigation schedule of said irrigationcontroller.
 13. The system of claim 12, wherein said sensor assemblycomprises a quick reacting rainfall detector and an accumulation typerainfall detector.
 14. The system of claim 12, wherein said hygroscopicsensor comprises a first hygroscopic sensor and a second hygroscopicsensor.
 15. A system for regulating an irrigation system comprising: asensor unit configured for operation at a remote location comprising: ahygroscopic sensor assembly capable of providing a plurality ofdifferent rain measurement values; and, a wireless transmitterconfigured to wirelessly transmit sensor data from said hygroscopicsensor assembly indicating a current rain measurement value; and acontrol module configured for operation local to an irrigationcontroller, comprising: a wireless communication unit that wirelesslyreceives said data wirelessly transmitted by said sensor unit; a modulecontrol circuit in communication with said wireless communication unit;a user interface in communication with said module control circuitry andbeing connectable to said irrigation controller to interrupt anirrigation schedule; wherein said sensor unit generates a quick reactingrainfall signal and an accumulation rainfall signal; and, wherein saidsensor unit and said control module are further operable to rapidlyinterrupt said irrigation schedule upon initiation of rain based on saidquick reacting rainfall signal and maintain interruption of saidirrigation schedule based on said accumulation rainfall signal when saidhygroscopic sensor exceeds a user-determined threshold of rain absorbedby said hygroscopic sensor.
 16. The system of claim 15, wherein saidhygroscopic sensor assembly comprises a plurality of vertically stacked,hygroscopic discs.
 17. The system of claim 15, wherein said hygroscopicsensor assembly comprises a first hygroscopic sensor and a secondhygroscopic sensor.
 18. The system of claim 15, wherein said hygroscopicsensor assembly comprises a quick reacting rainfall detector and anaccumulation type rainfall detector.